Nuclear energy: Radical reactors : Nature News & Comment

Nuclear energy: Radical reactors

For decades, one design has dominated nuclear reactors while potentially better options were left by the wayside. Now, the alternatives might finally have their day.

M. Mitchell Waldrop
05 December 2012

Back in 2000, when Kirk Sorensen was a NASA engineer looking at nuclear-power options for future colonies on the Moon, he came across a book that described the molten-salt reactor: an energy source in which the nuclear fuel was liquid.

It sounded bizarre, says Sorensen. Every reactor he had ever heard of used some form of solid uranium fuel — starting with the ‘light-water’ reactors that currently dominate the nuclear-power industry. But the book explained that the molten-salt technology had been demonstrated some three decades earlier at the Oak Ridge National Laboratory in Tennessee — and that the fluid uranium- or thorium-containing fuel offered major advantages. Molten-salt reactors would be impervious to catastrophic meltdown, for example, and instead of producing nuclear waste laced with plutonium and other long-lived radioisotopes, they could destroy those isotopes almost completely.

The list of advantages went on and on, says Sorensen: the molten-salt idea “had the potential to solve almost all the problems of nuclear energy in a far, far more elegant way” than light-water reactors. “So why didn’t we do it this way in the first place?”